Seemingly Harmless Foods to Stop Eating Before You Work Out

When Healthy Isn’t Enough

You know better than to go into a workout on empty—food equals fuel, after all. But just because something is good for your body normally doesn’t mean it’ll be good for your body in motion. “Every athlete and gym-goer is different regarding what they can handle; some have an iron stomach while, for others, the mere thought of something fibrous, fatty, sugary, or filling sends them scrambling to find a nearby restroom,” says Pam Nisevich Bede, RD, sports dietitian with Abbott’s EAS Sports Nutrition.

Before you hit the gym or head out on a run, erase these six seemingly harmless foods as options to fuel up with. (And if you’re a morning workout gal, check out the best foods to eat before and after your sweat sesh.)

Flaxseeds

Because flaxseeds are a good source of fiber, they’re a natural laxative and great for regulating your GI tract—but that’s not exactly the effect you want right before a run or a workout. “While a small serving of flaxseeds may help you clear your digestive tract, too much (especially without water) may cause constipation or loose stools,” explains sports dietitian Marni Sumbal, R.D., owner of Trimarni Coaching and Nutrition in Greenville, South Carolina. Stick to under two tablespoons and you’ll avoid any emergencies.

Smoothies

“While a smoothie can make for a healthy recovery meal post-workout, it’s not too difficult to make or order a sugar-filled, unhealthy shake,” Sumbal says. The result: Sky-high blood sugar levels, which will then crash your energy mid-circuit. Plus, a large volume of smoothie—or any liquid—increases the need to pee, Sumbal adds, and a bathroom break is less than ideal when you’re trying to keep your heart rate up consistently. Suck your smoothie down two hours before hitting the gym.

Nut Butter/Healthy Fats

“While items like avocado and nut butters are typically great choices, many people hitting a workout find that too much fat in the hours before exercising can leave them feeling leaden and weighed down,” Bede says. “Fat takes considerably more time to digest compared to carbs, and it’s not the high-octane, glycogen-creating fuel you need for your workout.” What’s more, the macronutrient can create acid reflux for many runners. Sumbal agrees, adding you should stick to less than 15 grams of fat pre-workout (that’s roughly one tablespoon of nut butter, one ounce of cheese, or two large eggs).

Coffee

“Drinks like tea, warm water with lemon, and coffee can be excellent choices when you need a quick pre-workout, well, clean out,” Bede explains. We’ve all experienced it—the warm liquid helps to activate and move your bowels. “Cut it too close or drink cup after cup of coffee on your way out the door and you could be mid-run when your system wants to ‘lighten up’—and that won’t be pretty,” she adds. But studies do show caffeine can help improve your endurance and training intensity, so if you want that boost, you have two options: Opt for caffeine tablets or powder which won’t cause the same GI distress, or, as Bede suggests, give yourself 20 minutes post-java to process the drink before heading out on your run.

Apples

Apples are a natural source of caffeine and carbs, so you might think they’d be great for a pre-workout snack. But high-residue foods—i.e., anything high in fiber—can cause GI distress or diarrhea during your workouts, Sumbal explains. Fiber is super important to help regulate your bowel movements, but you’re better off trading high-residue foods like apples and multi-grain bread for lower residue alternatives like applesauce or rice cakes, she adds.

Sports Drinks

Sugars like sorbitol, xylitol, isomalt, and mannitol aren’t fully absorbed by the gut, which may cause gas, bloating, cramping, and diarrhea, Sumbal explains. You know to avoid added sugars in the form of candy and juice, but these ingredients are common in sports drinks, electrolyte tablets, and sports bars. What’s more, you really don’t need the specialized drink. “While many people may be baptized on carb-rich, sugar-laden sports drinks, unless you’re working out for over an hour or in extreme conditions, water is likely your best bet,” Bede says. On a long run? There are hydration aids that won’t hurt your workout—the electrolyte-rich, sugar-free drinks. Just read the labels and avoid any added sugars.